/*
自己选择的路 ,跪着也要走完。朋友们 , 虽然这个世界日益浮躁起来,只
要能够为了当时纯粹的梦想和感动坚持努力下去 , 不管其它人怎么样,我
们也能够保持自己的本色走下去。
To the world , you will be a person , but to a person , you
will be the world .                               ——AKPower
*/
//作者:AKPower
//算法:
#include <iostream>
#include <cmath>
#include <algorithm>
#include <cstring>
#include <vector>
#include <map>
#include <queue>
#include <cstdio>
#include <string>
#include <stack>
#include <set>
#define IOS ios::sync_with_stdio(false), cin.tie(0)
using namespace std;
typedef long long ll;
const ll maxn = 1e5 + 100;
ll n, k;
ll x[maxn];

bool judge(ll d)
{
    ll cnt = 0;
    ll last = x[1];
    for (ll i = 2; i <= n; i++)
    {
        ll dis = x[i] - last;
        if (dis <= d)
        {
            last = x[i];
        }
        else
        {
            last = x[i];
            cnt += (dis - 1) / d;
        }
    }
    if (cnt > k)
        return false;
    else
        return true;
}

int main()
{
    IOS;
    cin >> n >> k;
    for (ll i = 1; i <= n; i++)
    {
        cin >> x[i];
    }
    sort(x + 1, x + 1 + n);
    ll l = 0, r = x[n] - x[1];
    ll ans = 0;
    while (l <= r)
    {
        ll mid = (l + r) >> 1;
        if (judge(mid))
        {
            r = mid - 1;
            ans = mid;
        }
        else
            l = mid + 1;
    }
    cout << ans << endl;
    getchar();
    getchar();
    return 0;
}
